CVE-2023-53601

Published Oct 4, 2025

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: bonding: do not assume skb mac_header is set Drivers must not assume in their ndo_start_xmit() that skbs have their mac_header set. skb->data is all what is needed. bonding seems to be one of the last offender as caught by syzbot: WARNING: CPU: 1 PID: 12155 at include/linux/skbuff.h:2907 skb_mac_offset include/linux/skbuff.h:2913 [inline] WARNING: CPU: 1 PID: 12155 at include/linux/skbuff.h:2907 bond_xmit_hash drivers/net/bonding/bond_main.c:4170 [inline] WARNING: CPU: 1 PID: 12155 at include/linux/skbuff.h:2907 bond_xmit_3ad_xor_slave_get drivers/net/bonding/bond_main.c:5149 [inline] WARNING: CPU: 1 PID: 12155 at include/linux/skbuff.h:2907 bond_3ad_xor_xmit drivers/net/bonding/bond_main.c:5186 [inline] WARNING: CPU: 1 PID: 12155 at include/linux/skbuff.h:2907 __bond_start_xmit drivers/net/bonding/bond_main.c:5442 [inline] WARNING: CPU: 1 PID: 12155 at include/linux/skbuff.h:2907 bond_start_xmit+0x14ab/0x19d0 drivers/net/bonding/bond_main.c:5470 Modules linked in: CPU: 1 PID: 12155 Comm: syz-executor.3 Not tainted 6.1.30-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:skb_mac_header include/linux/skbuff.h:2907 [inline] RIP: 0010:skb_mac_offset include/linux/skbuff.h:2913 [inline] RIP: 0010:bond_xmit_hash drivers/net/bonding/bond_main.c:4170 [inline] RIP: 0010:bond_xmit_3ad_xor_slave_get drivers/net/bonding/bond_main.c:5149 [inline] RIP: 0010:bond_3ad_xor_xmit drivers/net/bonding/bond_main.c:5186 [inline] RIP: 0010:__bond_start_xmit drivers/net/bonding/bond_main.c:5442 [inline] RIP: 0010:bond_start_xmit+0x14ab/0x19d0 drivers/net/bonding/bond_main.c:5470 Code: 8b 7c 24 30 e8 76 dd 1a 01 48 85 c0 74 0d 48 89 c3 e8 29 67 2e fe e9 15 ef ff ff e8 1f 67 2e fe e9 10 ef ff ff e8 15 67 2e fe <0f> 0b e9 45 f8 ff ff e8 09 67 2e fe e9 dc fa ff ff e8 ff 66 2e fe RSP: 0018:ffffc90002fff6e0 EFLAGS: 00010283 RAX: ffffffff835874db RBX: 000000000000ffff RCX: 0000000000040000 RDX: ffffc90004dcf000 RSI: 00000000000000b5 RDI: 00000000000000b6 RBP: ffffc90002fff8b8 R08: ffffffff83586d16 R09: ffffffff83586584 R10: 0000000000000007 R11: ffff8881599fc780 R12: ffff88811b6a7b7e R13: 1ffff110236d4f6f R14: ffff88811b6a7ac0 R15: 1ffff110236d4f76 FS: 00007f2e9eb47700(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e421000 CR3: 000000010e6d4000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> [<ffffffff8471a49f>] netdev_start_xmit include/linux/netdevice.h:4925 [inline] [<ffffffff8471a49f>] __dev_direct_xmit+0x4ef/0x850 net/core/dev.c:4380 [<ffffffff851d845b>] dev_direct_xmit include/linux/netdevice.h:3043 [inline] [<ffffffff851d845b>] packet_direct_xmit+0x18b/0x300 net/packet/af_packet.c:284 [<ffffffff851c7472>] packet_snd net/packet/af_packet.c:3112 [inline] [<ffffffff851c7472>] packet_sendmsg+0x4a22/0x64d0 net/packet/af_packet.c:3143 [<ffffffff8467a4b2>] sock_sendmsg_nosec net/socket.c:716 [inline] [<ffffffff8467a4b2>] sock_sendmsg net/socket.c:736 [inline] [<ffffffff8467a4b2>] __sys_sendto+0x472/0x5f0 net/socket.c:2139 [<ffffffff8467a715>] __do_sys_sendto net/socket.c:2151 [inline] [<ffffffff8467a715>] __se_sys_sendto net/socket.c:2147 [inline] [<ffffffff8467a715>] __x64_sys_sendto+0xe5/0x100 net/socket.c:2147 [<ffffffff8553071f>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff8553071f>] do_syscall_64+0x2f/0x50 arch/x86/entry/common.c:80 [<ffffffff85600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163